Arunima Sengupta 1, Aurélien Dorn 1,2, Mohammad Jamshidi 1, Magali Schwob1, Widad Hassan 1, Lea Lara De Maddalena 2, Andreas Hugi 2, Andreas O. Stucki 1, Patrick Dorn 3,4, Thomas M. Marti 3,4, Oliver Wisser 5, Janick D. Stucki 2, Tobias Krebs5, Nina Hobi 2 and Olivier T. Guenat1,3,6
1Organs-on-Chip Technologies, ARTORG Center for Biomedical Engineering, University of Bern, Bern, Switzerland,
2AlveoliX AG, Swiss Organs-on-Chip Innovation, Bern, Switzerland,
3Department of General Thoracic Surgery, Inselspital, Bern University Hospital, Bern, Switzerland,
4Department for BioMedical Research, University of Bern, Bern, Switzerland,
5VITROCELL Systems GmbH, Waldkirch, Germany,
6Department of Pulmonary Medicine, Inselspital, Bern University Hospital, Bern, Switzerland
This study described the establishment of three different exposure models with the Cloud α AX12 with varying multicellular complexities, where a crucial physiological impact of ALI and CS combined culture conditions could be conceived. The Cloud α AX12 platform recapitulates critical parameters of inhalation toxicity in the lung epithelium such as deposition kinetics, reproducible cytotoxic and barrier disruption effects in cell models of varying complexities along with deregulated gene and protein regulation representative of an inflamed barrier.
Prolonged exposure to environmental respirable toxicants can lead to the development and worsening of severe respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD) and fibrosis. The limited number of FDA-approved inhaled drugs for these serious lung conditions has led to a shift from in vivo towards the use of alternative in vitro human-relevant models to better predict the toxicity of inhaled particles in preclinical research. While there are several inhalation exposure models for the upper airways, the fragile and dynamic nature of the alveolar microenvironment has limited the development of reproducible exposure models for the distal lung. Here, we present a mechanistic approach using a new generation of exposure systems, the Cloud α AX12. This novel in vitro inhalation tool consists of a cloud-based exposure chamber (VITROCELL) that integrates the breathing AXLung-on-chip system (AlveoliX). The ultrathin and porous membrane of the AX12 plate was used to create a complex multicellular model that enables key physiological culture conditions: the air-liquid interface (ALI) and the three-dimensional cyclic stretch (CS). Human-relevant cellular models were established for a) the distal alveolarcapillary interface using primary cell-derived immortalized alveolar epithelial cells (AXiAECs), macrophages (THP-1) and endothelial (HLMVEC) cells, and b) the upperairways using Calu3 cells. Primary human alveolar epithelial cells (AXhAEpCs) were used to validate the toxicity results obtained from the immortalized cell lines. To mimic in vivo relevant aerosol exposures with the Cloud α AX12, three different models were established using: a) titanium dioxide (TiO2) and zinc oxide nanoparticles b) polyhexamethylene guanidine a toxic chemical and c) an antiinflammatory inhaled corticosteroid, fluticasone propionate (FL). Our results suggest an important synergistic effect on the air-blood barrier sensitivity, cytotoxicity and inflammation, when air-liquid interface and cyclic stretch culture conditions are combined. To the best of our knowledge, this is the first time that an in vitro inhalation exposure system for the distal lung has been described with a breathing lung-on-chip technology. The Cloud α AX12 model thus represents a state-of-the-art pre-clinical tool to study inhalation toxicity risks, drug safety and efficacy.